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Knowledge of boiler factory pipeline,and method of application

1. And inferior steel tube folding is seen.

Folding is formed on the surface of the pipe line, this kind of defect often throughout the entire

product longitudinal. Causes of fold is due to the pursuit of high efficiency, the fake, big reduction,

produce ErZi, under a rolling occurs when folding, folding products will be cracking after bending,

strength of steel.

(2) and inferior steel tube appearance often have pitted surface phenomenon.

Pits was caused by worn groove steel irregular uneven defects. Because want to pursuit of profit

and inferior steel pipe manufacturer, often appear groove rolling the overweight.

(3) and inferior steel tube surface are prone to scarring.

For two reasons: (1) and inferior steel pipe material uneven, impurities. (2). And inferior material

manufacturer guide equipment simple, easy to stick steel, these impurities are prone to scarring

after the roll bite.

4. Easy generation and inferior material surface crack, the reason is that it's blank is adobe,

adobe air, adobe after cooling

Process due to the effect of thermal stress, cracks, after rolling there is crack.

5. Easy to scratch and inferior steel pipe, the reason is false and inferior steel pipe factory

equipment simple, easy to produce burr, scratch steel surfaces. Deep scratches to reduce the

strength of the steel.

6. No metallic luster and inferior steel tube, reddish or similar to the color of the pig iron, two point

two, its billet is adobe reasons. 2, and inferior material rolling temperature is not standard, their

steel temperature is through visual inspection, so can't austenitic area of the rolling by the

regulation, the performance of the steel natural can't up to standard.7. And inferior steel pipe transverse reinforcement and low, often appear the phenomenon of

discontent, filling the reason is that manufacturers to achieve big minus tolerance, finished

product quantity of the previous way slants big, small iron type, pass to charge.

8 and inferior steel tube cross-section oval, because the factory in order to save material, the

quantity of the finished product roll before 2 slants big, the strength of rebar is greatly decreased,

but also do not conform to the standard of rebar shape size.

9. The high quality steel composition is uniform, cold shearing machine high tonnage, cutting

head end face smooth and neat, and shoddy material because the material is poor, cutting head

end face often have meat, or uneven, and no metallic luster. And due to low and inferior material

manufacturers cut head, end there will be a big ErZi.

More than 10. And inferior impurities in steel pipe material, steel small density, size and out-of-

tolerance is serious, so in the absence of vernier caliper, can be checked to weigh it. Such as for

rebar, 20 biggest minus tolerance specified in the national standard of 5%, scale 9 m in the theory

of single weight is 120 kg, it should be the smallest weight: 120 X (l - 5%) = 114 kg and 114 kg

weigh out the weight of the single than small, is false and inferior steel, the reason is that it is

negative tolerance more than 5%. In general the whole amount to match the effect will be better,

mainly considering the cumulative error

And the probability of this problem.

11. And inferior steel pipe diameter is volatile, the reason is; L have surface of Yin and Yang, the

steel temperature is not stable. 2, the composition of steel is not uniform. 3, due to poorly

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equipped, foundation strength is low, the mill bounce. There will be have the same within weeks

Change is bigger, the steel bar caused by uneven on fracture.

12. Logo and printing are of high quality tube specification.

13. More than three steel pipe diameter 16 big thread, the spacing between the two trademarks

are over IM.

14. And inferior steel rebar longitudinal reinforcement often undulate.

15. Since there is no traffic and inferior steel pipe manufacturer, so the packing is loose. Lateral

oval